I have a problem with activating HDR via DisplayPort. This is with a LG 34BK95U - 5120x2160 which requires DP 1.4 to get the full width. HDMI (which limits it to 3840 width) works fine.

Basically, it seems that madVR does not recognize that HDR is supported via DP, and thus always does tonemap HDR instead. (And I HAVE checked that HDR can be activated otherwise via DP.)

Steps To Reproduce

It only occurs with the above monitor (or probably with the 34WK95U which is identical) and only on the Displayport (1.4). Other than that, just play a HDR file with "passthrough HDR to display" set and "send HDR metadata to the display" checked and note that the HDR indicator does not appear and that the resulting image is from "tonemap HDR ..." instead.

I've included a log.

Additional Information

It may or may not be related, but the "identification" for this monitor is wrong, e.g. it shows NVIDIA for the manufacturer (among other things). (Again, this is only on the DisplayPort 1.4 input to this monitor - the HDMI input is fine and DisplayPort (1.2) inputs on other LG monitors are fine.) And Moninfo shows correct data for this DP 1.4 input.

Even stranger, additional identical identification entries keep getting added, always 2 at a time (but I don't know what triggers it). The data is identical for all, with all but the last grayed out. (I'm currently at 23 entries.)

I have exactly the same problem. It seems that there's something wrong with NVIDIA driver 416.94 or above, 416.81 is the last working driver version. MadVR said my display does not support HDR after I upgrade to 417.22, after rolling back to 416.81 everything works fine.

The problem reported directly above is NOT "exactly" the same problem as originally reported. On Win 8.1, the problem originally reported still exists with the Win 8.1 416.81 driver. I have not tested Win 10 with the 416.81 driver since I mostly use Win 8.1, although I previously tested it on Win 10 with more recent drivers.

Also, my problem is unique to to the Displayport connection on the 34WK/BK95 monitor. The HDMI port on this monitor is fine. I don't have any other monitor with both HDR and a Displayport so I don't know about any other monitor.

Information on the monitor used and whether it is on a Displayport would be very helpful.